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51.
52.
The present study documents the presence, in the serum of one allergic individual, of auto-anti-idiotypic antibodies cross-reacting with public idiotypic determinants expressed on human IgE and IgG anti-Rye I antibodies. Sera from rye-sensitive patients were tested for specific IgG and IgE antibodies to Rye I by double antibody. The IgG fraction, isolated from the serum of a patient with a history of previous hyposensitization therapy, was repeatedly absorbed on Rye-I-Sepharose as well as on IgM- and IgG-Sepharose to remove anti-Rye I antibodies as well as any possible anti-heavy or light chain activity. This IgG fraction, named anti-idiotypic fraction (a-IdF), blocked in a dose-dependent fashion the reaction of IgG and IgE anti-Rye I antibodies with Rye I antigen. The a-IdF also blocked the binding of anti-rye antibodies to Rye I antigen in the serum of 20 unrelated allergic patients, indicating that these anti-Rye I antibodies bore public idiotypic determinants.  相似文献   
53.
C Pop  Y R Chen  B Smith  K Bose  B Bobay  A Tripathy  S Franzen  A C Clark 《Biochemistry》2001,40(47):14224-14235
We have investigated the oligomeric properties of procaspase-3 and a mutant that lacks the pro-domain (called pro-less variant). In addition, we have examined the interactions of the 28 amino acid pro-peptide when added in trans to the pro-less variant. By sedimentation equilibrium studies, we have found that procapase-3 is a stable dimer in solution at 25 degrees C and pH 7.2, and we estimate an upper limit for the equilibrium dissociation constant of approximately 50 nM. Considering the expression levels of caspase-3 in Jurkat cells, we predict that procaspase-3 exists as a dimer in vivo. The pro-less variant is also a dimer, with little apparent change in the equilibrium dissociation constant. Thus, in contrast with the long pro-domain caspases, the pro-peptide of caspase-3 does not appear to be involved in dimerization. Results from circular dichroism, fluorescence anisotropy, and FTIR studies demonstrate that the pro-domain interacts weakly with the pro-less variant. The data suggest that the pro-peptide adopts a beta-structure when in contact with the protein, but it is a random coil when free in solution. In addition, when added in trans, the pro-peptide does not inhibit the activity of the mature caspase-3 heterotetramer. On the other hand, the active caspase-3 does not efficiently hydrolyze the pro-domain at the NSVD(9) sequence as occurs when the pro-peptide is in cis to the protease domain. Based on these results, we propose a model for maturation of the procaspase-3 dimer.  相似文献   
54.
Recent advances in DNA sequencing technologies have enabled the current generation of life science researchers to probe deeper into the genomic blueprint. The amount of data generated by these technologies has been increasing exponentially since the last decade. Storage, archival and dissemination of such huge data sets require efficient solutions, both from the hardware as well as software perspective. The present paper describes BIND-an algorithm specialized for compressing nucleotide sequence data. By adopting a unique 'block-length' encoding for representing binary data (as a key step), BIND achieves significant compression gains as compared to the widely used general purpose compression algorithms (gzip, bzip2 and lzma). Moreover, in contrast to implementations of existing specialized genomic compression approaches, the implementation of BIND is enabled to handle non-ATGC and lowercase characters. This makes BIND a loss-less compression approach that is suitable for practical use. More importantly, validation results of BIND (with real-world data sets) indicate reasonable speeds of compression and decompression that can be achieved with minimal processor/ memory usage. BIND is available for download at http://metagenomics.atc.tcs.com/compression/BIND. No license is required for academic or non-profit use.  相似文献   
55.
Using steady-state relaxation spectrophotometric technique a P700 component (t 12 ~20 ms) has been detected which was sensitized by low concentration (10?7M) DCMU in isolated broken chloroplasts of pea. The relative quantum yield of electron flux through DCMU-sensitized P700 was similar to that with methyl viologen or NADP as terminal electron acceptor and water as electron donor. Kinetic analysis showed that a small fraction (10%) of the total P700 reaction centers was sensitized by low DCMU.  相似文献   
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Summary Ruellia tweediana and R. tuberosa are large flowered chasmogamous diploids (n=17) with normal meiosis and fertility. F1 hybrids, successful in only one direction (R. tweediana x R. tuberosa), are vegetatively vigorous and possess 17 often heteromorphic bivalents with high degree of segregational irregularities. It is exclusively cleistogamous and completely pollen and seed sterile. Like F1, the artificial amphidiploid (n=34) is also cleistogamous but shows preferential chromosome pairing with complete restoration of fertility. The parental chromosomes are sufficiently differentiated and cleistogamy is either genie or due to gene-cytoplasm interaction but sterility is entirely chromosomal. All floral parts excepting calyx are highly deformed. Such a deformity is associated with sterility in the F1 but with fertility in the amphidiploid. This is perhaps the first case of origin by hybridization of a true breeding and fully fertile cleistogamous taxon from two chasmogamous species. It also shows the extent and nature of change in breeding system brought about by hybridization and/or polyploidy.The chromosome numbers in the six, out of 16, obligate cleistogamous taxa (Table 4) show that they are high polyploids. Perhaps their origin has been in the same manner as in the present case.
Zusammenfassung Ruellia tweediana und R. tuberosa sind großblütige, chasmogame Diploide (n=17) mit normaler Meiosis und Fertilität. Die F1-Hybriden, die nur in einer Richtung gelingen (R. tweediana x R. tuberosa), sind vegetativ kräftig und besitzen häufig 17 heteromorphe Bivalente mit einem hohen Anteil an Spaltungsunregelmäßigkeiten. Die Hybride ist ausschließlich kleistogam und vollkommen pollen- und samensteril. Wie die F1 ist auch die künstlich hergestellte Amphidiploide (n=34) kleistogam und zeigt eine präferentielle Chromosomenpaarung mit völliger Wiederherstellung der Fertilität. Die elterlichen Chromosomen sind genügend differenziert. Die Kleistogamie ist entweder genisch bedingt oder auf eine Gen-Cytoplasma-Interaktion zurückzuführen, die Sterilität ist ausschließlich durch die Chromosomen verursacht. Alle Teile der Blüte mit Ausnahme der Calyx sind stark deformiert. Bei der F1 ist diese Deformation mit Sterilität verbunden, die amphidiploide Form ist jedoch fertil. Das ist vielleicht der erste Fall eines aus der Kreuzung zweier chasmogamer Spezies hervorgegangenen reinerbigen und voll fertilen kleistogamen Taxons. Es läßt sich auch der Umfang und die Art der durch Hybridisierung und durch Polyploidie verursachten Änderung des Zuchtsystems erkennen. Die Chromosomenzahl bei 6 von 16 obligaten kleistogamen Taxa (Tab. 4) zeigt, daß sie hochpolyploid sind. Vielleicht sind sie auf eine gleiche Weise wie im vorliegenden Falle entstanden.
  相似文献   
57.
The polypeptides of reticuloendotheliosis virus (REV) were separated by gel filtration in the presence of guanidine hydrochloride. The eight peaks obtained by gel filtration were then analyzed by polyacrylamide gel electrophoresis and four appeared to contain single polypeptides. The material identified as p29 was used to prepare antiserum. This protein constitutes the major internal non-glycosylated polypeptide in the virion. Double immunodiffusion indicated that the antiserum was specific for p29. Using this antiserum, cross-reactivity was demonstrated between REV, chick syncytial virus, duck infectious anemia virus, and spleen necrosis virus. Antiserum to p29 failed to cross-react with Rous sarcoma virus. This indicates that p29 is a group-specific antigen shared by the viruses of the REV complex. A microcomplement fixation test was developed with this antiserum that will be useful in the quantitation of REV and the identification of other members of this newly defined group.  相似文献   
58.
BackgroundTriple negative breast cancer (TNBC) is the most aggressive form of breast cancer with limited treatment modalities. It is associated with high propensity of cancer recurrence.MethodsUV Spectroscopy, FTIR, DLS, Zeta potential, TEM and SEM were employed to characterize nanoparticles. MTT assay, Wound healing assay, SEM, Immunocytochemistry analysis, Western blot, RT-PCR, mammosphere formation assay were employed to study apoptosis, cell migration and stemness. Tumor regression was studied in chick embryo xenograft and BALB/c mice model.ResultsHylaluronic acid engrafted metformin loaded graphene oxide (HA-GO-Met) nanoparticles exhibited an anti-cancer efficacy at much lower dosage as compared to metformin alone. HA-GO-Met nanoparticles induced apoptosis and inhibited cell migration of TNBC cells by targeting miR-10b/PTEN axis via NFkB-p65. Upregulation of PTEN affected pAKT(473) expression that induced apoptosis. Cell migration was inhibited by reduction of pFAK/integrinβ1 expressions. Treatment inhibited epithelial mesenchymal transition (EMT) and reduced stemness as evident from the increase in E-cadherin expression, inhibition of mammosphere formation and low expression levels of stemness markers including nanog, oct4 and sox2 as compared to control. Moreover, tumor regression was studied in chick embryo xenograft and BALB/c mice model. HA-GO-Met nanoparticle treatment reduced tumor load and nullified toxicity in peripheral organs imparted by tumor.ConclusionsHA-GO-Met nanoparticles exhibited an enormous anti-cancer efficacy in TNBC in vitro and in vivo.General significanceHA-GO-Met nanoparticles induced apoptosis and attenuated cell migration in TNBC. It nullified overall toxicity imparted by tumor load. It inhibited EMT and reduced stemness and thereby addressed the issue of cancer recurrence.  相似文献   
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Mycobacillin non-producers, whether sporogenous or asporogenous, possess less exoprotease, but effective exoprotease producers are not always good mycobacillin yielders. There might exist a minimum level of exoprotease formation for elaboration of mycobacillin.  相似文献   
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